Digital video was once believed to be a medium of unlimited supply. With a few clicks, one could purchase wide swaths of inventory through automated marketplaces. So the thought of buying it ahead of time, or "upfront" like TV, seemed ludicrous.

But for now, the reality might look a bit different, at least according to AOL video head Ran Harnevo. In a video interview with Ad Age Mr. Harnevo argued that while video proliferates online, the amount of premium inventory available is actually rather scarce. So advertisers, he said, are eager to lock in deals early to avoid being shut out of the best content.

That, Mr. Harnevo said, is a big reason why AOL plans to "double down" on original video. Expect to hear more about this when the company presents during the Digital Content Newfronts next month